Adding a quotation marks message to core.

Needed for...
https://wikimedia.mingle.thoughtworks.com/projects/mobile/cards/1218

This could be implemented in MobileFrontend, but it seems generic
enough to be put in core.

Change-Id: Iebf628052ea14f0fb8b931d7c37a0501a24d3d45
Merge "Adding a quotation marks message to core."